Heat exchanger

ABSTRACT

A heat exchanger in which the exchanger comprises inner and outer tubes spaced apart to define a fluid passage but sealed at the opposite extremities of the passage, a pair of spaced fittings communicating with the fluid passage for flow of fluid into, through and from the passage, a fluid turbulizer in the passage comprising flat stock with laterally projecting integral strips to create turbulence in the fluid flowing through the passage and resulting superior heat transfer with the turbulizer having end portions terminating short of the extremities of the passage to define a pair of end header spaces and a direct flow path from one fitting means and the nearer header space in collapsed or flattened condition so that the strips in this area provide substantially no impediment to fluid flow from the fitting means to the nearer header space.

United States Patent [191 Hilicki et al.

[ 1 May 15, 1973 [54] HEAT EXCHANGER [75] Inventors: Edwin J. Hilicki,Racine, Wis;

Harry J. Schroeder, Lake Bluff, ill.

[73] Assignee: Modine Manufacturing Company,

Racine,Wis.

[22] Filed: June 30, 1971 [21] Appl. No.: 158,297

Jones Burne et al. ..l65/l54 Primary Examiner-Charles J. Myhre AssistantExaminer-Theophil W. Streule, Jr. A tt0rney- Axel A. Hofgren et al.

[57] ABSTRACT A heat exchanger in which the exchanger comprises innerand outer tubes spaced apart to define a fluid passage but sealed at theopposite extremities of the passage, a pair of spaced fittingscommunicating with the fluid passage for flow of fluid into, through andfrom the passage, a fluid turbulizer in the passage comprising flatstock with laterally projecting integral strips to create turbulence inthe fluid flowing through the passage and resulting superior heattransfer with the turbulizer having end portions terminating short ofthe extremities of the passage to define a pair of end header spaces anda direct flow path from one fitting means and the nearer header space incollapsed or flattened condition so that the strips in this area providesubstantially no impediment to fluid flow from the fitting means to thenearer header space.

4 Claims, 7 Drawing Figures 1 HEAT EXCHANGER BACKGROUND OF THE INVENTIONThe heat exchanger of this invention is related to the In FIGS. 1 and 2there is disclosed a heat exchanger tubular types of heat exchanger inwhich a fluid flow comprising an outer tube 11, an inner tube 12 withinpath is provided between two tubes, one outer and one inner and spacedapart in a region to provide a fluid passage therebetween so that fluidcan not only flow in this passage but other fluid may contact the innerand outer tubes to provide heat transfer between all of the fluids.

It is customaryto provide fluid turbulizers in this passage between thetubes and to provide spaced fittings for flow of fluid into, through andfrom the space and to have the turbulizers shorter than the spacebetween the tubes so as to result in end header spaces that are free ofthe turbulizers.

In this invention the turbulizer which principally comprises laterallyprojecting strips of stock material has these strips collapsed in anarea between one fitting means and the nearer header space so as toprovide direct flow from the fitting means into the header space withoutsubstantial short-circuiting of the fluid directly from the fittingmeans into the turbulizer.

With the structure of this invention the confining of the flow from thefitting into the one header space is easily and inexpensivelyaccomplished merely by flattening or collapsing the turbulence promotingstrips in the desired area so that there is less resistance to fluidflow in this area then in the remainder of the turbulizer. With thisinvention the spacing of the fittings can be standardized to onedistance and the cooling capacity can be increased or decreased bycontrolling the length of the heat exchanger tubes. Within a widelatitude the length of the heat exchanger can be any value desiredbecause the collapsed turbulizer strips permit the directing of thefluid from the fitting to the adjacent header space regardless of thelength. In general, only one collapsed area of turbulizer strip will berequired for each heat exchanger but, if desired, each fitting may ofcourse have its own direct flow path into its nearer header space byproviding it with the collapsed strips.

The most pertinent prior art of which applicants are aware are Dedo U.S.Pat. No. 2,752,128, Straubing U.S. Pat. No. 3,001,767 and Zeidler U.S.Pat. No. 3,083,662 each of which discloses tubular heat exchanger withturbulizers made of expanded or distorted flat stock. However, in noneof these are there provided direct flow paths of the type disclosed andclaimed herein.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a shortened side elevationalview partially in section illustrating a tubular heat exchangerembodying the invention.

FIG. 2 is a sectional view taken substantially along line 2-2 of FIG. 1.

FIG. 3 is an enlarged perspective view of a section of a turbulizer thatmay be used in this invention.

FIG. 4 is a fragmentary plan view of one end of turbulizer of thisinvention.

FIG. 5 is a side elevational view of the turbulizer of FIG. 4.

FIG. 6 is an end elevational view of the portion of the turbulizer ofFIGS. 4 and 5.

FIG. 7 is a view similar to FIG. 6 but illustrating a further embodimentof the invention.

the

seal 14 and 15 at the opposite ends of the tubes 11 and 12 to define theextremities of the fluid passage 13.

The heat exchanger is provided with a pair of spaced apart fitting means16 and 17 in the form of ordinary pipe fittings for providingcommunication with the fluid passage 13. One fitting 16 is adjacent theend of the tube to communicate with a header space 18 while the otherfitting 17 is spaced inwardly of the other end of the heat exchanger andfrom the other header space 19. These fittings 16 and 17 are similar tothe fittings in the above referred to patents in that they provide fluidflow into, through and from the fluid passage 13.

Positioned in the fluid passage 13 is a turbulizer 20 having endsterminating short of the passage 13 to provide the end header spaces 18and 19. This turbulizer customarily comprises laterally projectingintegral strips so as to create turbulence in fluid flowing between andaround the strips. Typical turbulizers are disclosed in the abovepatents and one type is shown in enlarged detail in FIG. 3 whichillustrates only a fragment of a turbulizer. This type of turbulizer isdisclosed in greater detail in Dedo U.S. Pat. No. 2,752,128 and itcomprises flat stock 21 having integral strips 22 and 23 projectingtherefrom.

In the turbulizer of this invention a direct flow path is provided fromone or both of the fittings 16 and 17 directly to the nearer headerspace. In the embodiment of FIGS. 1 and 2 the one fitting 16 is locatedadjacent a header space 18 while the other fitting 17 is spaced from theother header space 19 and the direct flow path 24mm the fitting 17 tothe nearer header space 19 is provided by collapsing or flattening thesespaced turbulizer strips as illustrated at 22 and 23. i

In the embodiment of FIGS. 4, 5 and 6 this flattening of the expandedmetal strips 22 and 23 is into the plane of the flat stock as describedand the resulting structure is corrugated as illustrated at 25 toprovide parallel flow from the fitting 17 to the header space 19. Suchcorrugating is not required, however, although it does give addedstrength to the part. If desired, the corrugations may be omitted asillustrated in the embodiment of FIG. 7 so that the flat stock andcollapsed strips are all in a single plane that follows the generalcurvature of the turbulizer thereby providing a large header reservoir27. Actually, of course, the collapsed strips are in a common plane witheach other and with thestock even in FIG. 6 which shows the corrugatedconstruction. In FIG. 7 the collapsed coplanar strips are against thetube 12.

As can be seen from the above description, the heat exchanger of thisinvention provides an efficient but inexpensive heat exchanger thatdirects fluid from one or both of the fittings into the nearer headerspace without requiring added conduits, drains or the like. In theillustrated structure the seals 14 and 15 defining the opposite ends ofthe fluid passage 13 are arranged by making the corresponding ends ofthe inner and outer tubes contiguous and joined together. This is easilyaccomplished by bending the ends of one or both tubes into thecontiguous relationship as by enlarging the opposite ends of the innertube 12 into contact with the inner surface of the outer tube 11 in themanner illustrated in FIG. 1.

As is illustrated in FIGS. 4-7 it is customary to provide the turbulizerin two semi-cylindrical sections so that when they are located withinthe fluid passage 13 they form generally a cylinder.

Having described our invention as related to the embodiments shown inthe accompanying drawings, it is our intention that the invention be notlimited by any of the details of description, unless otherwisespecified, but rather be construed broadly within its spirit and scopeas set out in the appended claims.

We claim:

1. A heat exchanger, comprising: an outer tube; an inner tube thereinand spaced therefrom to define a fluid passage therebetween; a pair ofspaced seal means between said tubes for defining opposite extremitiesof said passage; a pair of spaced fittings for directing a fluid in astream to, through and from said fluid passage; a fluid turbulizer insaid fluid passage extending substantially circumferentially therearound and having projecting portions spaced from each other bothlaterally and longitudinally and spanning the passage, said turbulizerhaving end means for defining with said pas sage a pair of end headerspaces; and means comprising collapsed said projecting portions adjacenta said fitting for providing a direct flow path at-said one fitting tothe nearer of the header spaces.

2. The heat exchanger of claim 1 wherein said turbulizer comprises flatstock, and said collapsed said strips provide substantially parallelcorrugated flow paths for rapid flow of fluid and added strength.

3. The heat exchanger of claim 1 wherein said collapsed strips aresubstantially coplanar to provide a header reservoir.

4. The heat exchanger of claim 1 wherein the opposite ends of said irmertube are enlarged relative to the remainder of said inner tube to engagethe outer tube and define the end limits of said header spaces.

1. A heat exchanger, comprising: an outer tube; an inner tube thereinand spaced therefrom to define a fluid passage therebetween; a pair ofspaced seal means between said tubes for defining opposite extremitiesof said passage; a pair of spaced fittings for directing a fluid in astream to, through and from said fluid passage; a fluid turbulizer insaid fluid passage extending substantially circumferentially therearound and having projecting portions spaced from each other bothlaterally and longitudinally and spanning the passage, said turbulizerhaving end means for defining with said passage a pair of end headerspaces; and means comprising collapsed said projecting portions adjacenta said fitting for providing a direct flow path at said one fitting tothe nearer of the header spaces.
 2. The heat exchanger of claim 1wherein said turbulizer comprises flat stock, and said collapsed saidstrips provide substantially parallel corrugated flow paths for rapidflow of fluid and added strength.
 3. The heat exchanger of claim 1wherein said collapsed strips are substantially coplanar to provide aheader reservoir.
 4. The heat exchanger of claim 1 wherein the oppositeends of said inner tube are enlarged relative to the remainder of saidinner tube to engage the outer tube and define the end limits of saidheader spaces.